The present invention relates to heating and cooling systems, more particularly to an improved heating and cooling system and method using rotating turbomachinery.
In many heat powered cycles, such as for cooling and heating, reciprocating types of equipment are used e.g., piston type pumps and compressors. In such cases, especially for cooling systems such as vehicular air conditioning, a compressor driven by a motor is used because the system cost is cheaper. The use of piston type equipment usually requires different fluids, especially for lubrication of the reciprocating equipment, and the presence of different fluids sometimes creates problems in the system. Present reciprocating systems require a shaft seal which is subject to leakage thus releasing the working fluid, e.g., hologenated hydrocarbon, into the atmosphere.
The use of heat as the power source has not received attention and use because of the fact that when heat is used as the power source, there is the requirement for a substantial number of reciprocating parts in the system and both the number of parts and lubrication requirements create problems of reliablity and systems efficiency, even though the cost of operation is less. Where there have been attempts to use heat power for cooling and heating, reciprocating equipment has generally been used. In recent years, with the costs of energy rising, cost of equipment has been less of a consideration if there can be a savings in energy.
In the case of vehicular cooling systems, the fuel energy needed to drive the systems has become a factor because of fuel costs. Thus, heat powered cooling systems, especially those powered by waste heat such as hot engine exhaust gases, have become more attractive, providing the system is sufficiently efficient to provide the needed cooling, provided the cost of the system is economically attractive.
It is also desirable to provide a system which may be used as both a cooling system and a heat pump such that the system may be adapted for residential uses as a heat pump in the cool seasons and as a cooling system in the warmer seasons. Typically, hydrocarbon gases may be used as the primary power source with a heat pump system as a heating package or as a cooling unit. In some portions of the country, part or all of the power may be solar power for both heating and cooling.
There are advantages in the use of rotating equipment such as turbomachinery in cooling and heating systems, such as fewer parts and substantial reduction in lubrication problems and reduction in possible contamination of heat exchanger surfaces by the lubricant. Also the number of moving parts is reduced and rotating equipment traditionally is more reliable than reciprocating equipment.